The present invention concerns an assembly formed by a wheel rim and an inflatable tire tread bearing support inflated to a given pressure, the said assembly, together with a tire, forming a rolling assembly that can allow the said tire to roll when its pressure is low or even zero. The said rim, designed for the mounting of the tire, is more particularly a rim with at least one rim seat inclined towards the outside.
U.S. Pat. No. 6,092,575 describes a wheel rim of the type mentioned above. It comprises at least a first truncated conical rim seat whose generatrix has an axially external end on a circle with diameter smaller than the diameter of the circle on which the axially internal end of the said generatrix is located. The truncated conical seat is extended axially outwards by a projection or hump whose outside diameter is smaller than the diameter of the axially internal end of the rim seat's generatrix. In the preferred shape of the rim, the said first rim seat is extended axially inwards by a bearing surface designed to receive a support ring for the tread, which is deformable and can be pushed over the said surface. Limited axially by a rim stop designed to keep the bearing support in its axial position, the said bearing surface is extended by a mounting groove which is needed to enable the tire beads to be positioned on the rim. The rim is completed by the addition of a second rim seat also inclined outwards and extended axially on the inside by a projection and axially inwards by a flange that connects to the mounting groove.
The tire tread bearing support generally used with the rim described above is a bulky, rigid support made of an elastomeric or plastic material. Besides, it is heavy despite the numerous cavities between its base and its crown. However, supports for rolling at low or zero tire pressure should be as light as possible, they should have as high a load-bearing capacity as possible without affecting their lightness, and should allow the driver of a vehicle fitted with them to control his vehicle despite the loss of pressure, more especially if the said loss takes place when the tire is rolling under the action of drift stresses.